Summary: Users are experiencing mixed results when using live editing. The first time you open a doc for live editing it is fine, and works as intended. Then, the 2nd time it opens up read only and wont allow the user to save changes. This is being caused by an update to Microsoft Office on newer versions of the Office Suite.
Users on Office Versions newer than 1902 are effected by this issue.
Office 2019 version 1808 which is what gets installed straight from the Microsoft Office website works fine.
Office 2016 and 2019 Version 1905 and up (1908 is latest) does not work correctly with live editing. The issue occurring is this: the first time you open a doc for live editing it is fine, and works as intended. Then, the 2nd time it opens up read only and wont allow the user to save changes. This did not happen in prior versions.
There is 2019, Office Pro Plus 365, and Office 16. Currently the latest version for Office Pro Plus 365 is 1902 and its good at the moment. The update by Microsoft that has caused this issue happened in August 2019.
Versions with issues- office 2019 version 1905 and up
Versions with issues- office 2016 version 1905 and up
The current recommended workaround for this is to disable lived editing, and instruct users to check out, edit your document, and when checking back in the document, upload the edited document.
Optionally, staying on an office version below 1902 would allow this functionality to continue to work as well.
You can check and see what version your office is using by opening word, going to "account" and checking the right side column under "about word"